Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
  • B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
  • B23K35/38—Selection of media, e.g. special atmospheres for surrounding the working area
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
  • B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
  • B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
  • B23K35/24—Selection of soldering or welding materials proper
  • B23K35/28—Selection of soldering or welding materials proper with the principal constituent melting at less than 950 degrees C
  • B23K35/282—Zn as the principal constituent
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
  • B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
  • B23K35/24—Selection of soldering or welding materials proper
  • B23K35/28—Selection of soldering or welding materials proper with the principal constituent melting at less than 950 degrees C
  • B23K35/286—Al as the principal constituent
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
  • B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
  • B23K35/24—Selection of soldering or welding materials proper
  • B23K35/30—Selection of soldering or welding materials proper with the principal constituent melting at less than 1550 degrees C
  • B23K35/302—Cu as the principal constituent
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
  • B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
  • B23K35/38—Selection of media, e.g. special atmospheres for surrounding the working area
  • B23K35/383—Selection of media, e.g. special atmospheres for surrounding the working area mainly containing noble gases or nitrogen
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K2103/00—Materials to be soldered, welded or cut
  • B23K2103/02—Iron or ferrous alloys
  • B23K2103/04—Steel or steel alloys
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K2103/00—Materials to be soldered, welded or cut
  • B23K2103/08—Non-ferrous metals or alloys
  • B23K2103/10—Aluminium or alloys thereof
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K2103/00—Materials to be soldered, welded or cut
  • B23K2103/18—Dissimilar materials
  • B23K2103/20—Ferrous alloys and aluminium or alloys thereof

Definitions

• the invention relates to a method of arc joining a workpiece under a protective gas with a consumable electrode using a short arc in which material is transferred from the consumable electrode to the workpiece to form an electronically controlled electrical short circuit.
• Arc joining under protective gas is a widely used joining technique.
• an arc burns between a arranged in a burner electrode and the workpiece to be machined.
• a welded joint is created by melting the base material at the processing point in the arc and then re-solidifying the material. If a consumable electrode is used, the material of the electrode enters the welded joint as an additional material.
• the cohesive connection is formed by the molten and re-solidified solder, which is added as filler material.
• the base material is not melted, but rather creates a bracing of solder and base material. When brazing with an arc usually a consumable electrode is used.
• the transition of the electrode material there are different variants, which also lead to differently burning arcing.
• the spray arc the globular droplet transition arc, the rotating arc with droplet transition, and the short arc.
• the short-arc occurs between the electrode and the workpiece, which is poled as a second electrode, during the electrode material transition, so when the liquid or doughy material begins to dissolve from the electrode and formed a bridge between the electrode and the workpiece, an electrical short circuit.
• the short-circuit causes the drop beginning to detach from the electrode to be pinched off, whereupon the drop detaches from the electrode.
• the electric field which is now present again after the short-circuit has been released, the arc ignites again. A new cycle begins.
• the short arc of all arc types has the lowest heat input.
• this good prerequisite concerning heat input methods of short arc welding and brazing has recently been developed with a view to minimizing heat input.
• the prerequisite for this was the possibility of electronic controllability.
• the electronic control reduces the short-circuit current in the first place, so that the heat input back into the workpiece.
• the abruptness with which the short-circuiting bridge travels and the material transfer takes place is alleviated, so that the welding spatters decrease markedly.
• the electronic control usually affects the current and voltage values. Partly also the wire promotion is included in the control.
• the invention has for its object to provide a method which increases the Wiederzündatom the electronically controlled short arc, so that high quality welds and solder joints arise even at high processing speeds.
• the object is achieved in that the protective gas used from 50 to 5000 vpm (0.005 to 0.5 vol .-%) oxygen, carbon dioxide, nitrogen monoxide, nitrogen, nitrous oxide or a mixture of these gases in argon or in an argon helium Mixture exists.
• the method according to the invention leads to an improved re-ignitability of the arc. This makes the entire joining process much more stable and therefore easier to control.
• the welding or solder seam is uniformly filled with the additional material, a constant bead is produced and also the pore frequency is significantly reduced.
• the improved re-ignitability is due to the properties of the protective gas mixture used.
• the oxygen / carbon dioxide / nitrogen monoxide / nitrogen / dinitrogen monoxide contained as doping gas in the protective gas mixture are deposited on the surface of the workpiece. At these points, there is a field elevation of the electric field, which results from the application of the welding voltage between the electrode and the workpiece. At these points the plasma formation begins. First, only the argon ionizes. Due to the liberated during the ionization Electrons begin to burn the arc, which greatly increases the energy input. Now workpiece material evaporates and the vaporized material ionizes.
• the protective gas contains 10 to 40 vol .-% helium.
• the proportion of helium should not exceed the upper limit, so that sufficient argon is contained in the shielding gas, so that the plasma formation begins swiftly and stably. If less helium than specified is contained in the protective gas, an influence on the welding process due to the high heat conductivity of helium is not noticed.
• Prefers is contained in the inert gas 25 to 35 vol .-% helium. With these helium fractions, these helium-based properties of the protective gas are particularly pronounced.
• the shielding gas preferably contains from 200 to 600 vpm (0.02 to 0.06% by volume) of oxygen, carbon dioxide, nitrogen monoxide, nitrogen, dinitrogen monoxide or a mixture of these gases. With this doping the Wiederzündein is supported particularly advantageous.
• the method according to the invention has the above-mentioned advantages in a particularly excellent manner when the protective gas consists of 300 vpm (0.03 vol.%) Of oxygen, 30 vol.% Of helium and argon in the remaining volume residue. Furthermore, it has been shown that, when doping with carbon dioxide, the advantages of the invention also for a shielding gas mixture consisting of 300 vpm (0.03 vol .-%) of carbon dioxide, 25 to 30 vol .-% helium and argon in set the remaining volume. When doping with nitrogen monoxide, it is advisable to use a protective gas consisting of 300 vpm (0.03% by volume) of nitrogen monoxide, 30% by volume of helium and the rest of argon.
• the method according to the invention shows its advantages when workpieces with a thickness of less than 5 mm, preferably less than 3 mm are available. So even with thin sheets with wall thicknesses of a few millimeters joints without holes can be achieved.
• workpieces made of aluminum or aluminum alloys are welded. Due to the low concentration of the doping gases, no metallurgical reaction occurs and the advantages of the invention can also be found in these sensitive materials.
• workpieces made of steel alloys are welded. These materials also show the advantages of the method according to the invention.
• a workpiece made of aluminum or aluminum alloys with a workpiece made of steel or coated steel with a solder based on aluminum Due to the very low heat input of the method according to the invention high-quality joints can also be made from these different materials. This is just possible for coated and especially for galvanized steel.
• the workpiece melts from aluminum or aluminum alloys while the steel workpiece is only heated. The cohesive connection is thus a mixed form of welding and soldering.
• workpieces made of coated or uncoated steel alloys are soldered to a solder based on copper r-aluminum or copper-silicon base. Even in the case of brazing with an arc, the re-ignitability of the electronically controlled arc is increased by the method according to the invention.
• the aforementioned explanations also apply to soldering since the ignition mechanism and the plasma formation are almost identical for these two joining techniques.
• a workpiece made of aluminum or an aluminum alloy is soldered to a workpiece made of steel or coated steel with a zinc-based solder.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Arc Welding In General (AREA)

Applications Claiming Priority (1)

Publications (2)

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ID=35457965

Family Applications (1)

Country Status (3)

Cited By (7)

Families Citing this family (6)

Citations (4)

Family Cites Families (3)

• 2005
  • 2005-08-26 DE DE102005040552A patent/DE102005040552A1/de not_active Withdrawn
  • 2005-10-04 EP EP05021653.0A patent/EP1757401B1/fr not_active Revoked
• 2006
  • 2006-08-15 US US11/504,888 patent/US20070045237A1/en not_active Abandoned

Patent Citations (4)

Non-Patent Citations (1)

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